Elgg\Http\ResponseFactory::stringify PHP Метод

    public function stringify($content = '')
    {
        $content = $this->normalize($content);
        if (empty($content) || is_object($content) && is_callable($content, '__toString')) {
            return (string) $content;
        }
        if (is_scalar($content)) {
            return $content;
        }
        return json_encode($content, ELGG_JSON_ENCODING);
    }